Welding electrode



June 13, 1944. POWELL 2,351,230

WELDING ELECTRODE Filed Dec. 5, 1942' l 1' I", ns. I "I' 11' 1 M INVEN TOR 40 aapowsu ATTQRNE) Patented June 13, 1944 UNITED" STATES PATENT OFFICE Raymond E. Powell, Westfleld, N. 1., assignor to Western Electric Company. Incorporated, New York, N. Y., a corporation of New York Application December 5, 1942, Serial No. 467,941 1 Claim. (Cl. 219-4) This invention relates to welding electrodes, particularlythose of the fluid cooled type, and methods of making the same.

It is needless to say that welding electrodes are subjected to exceedingly high temperatures, particularly when employed for repeated operations on work. It is advantageous, therefore, insuch instances to cool the electrodes with a cooling medium which'may be circulated through the electrodes to positions in close proximity to the work faces thereof. Various cooling media. may be employed, yet the effectiveness of the cooling is in proportion to the temperature gradient between the work-face and the temperature of the cooling medium being employed. Furthermore, the effectiveness of the gradient is in proportion to the area exposed to the cooling medium, and if this area is increased, the amount of heat transferred will be increased in the same ratio as the area is increased and thus the cooler will be the work face.

Objects of the invention are to provide an electrode for use in welding and a method of making the same so that it has a large'heat transfer area whichmay be subjected to a cooling medium.

With these and other objects in view, the invention comprises a welding electrode and the meth:

- d of making it by forming therein a passageway, for a cooling 'fluid, the walls of which provide a heat, transfer area terminating short of the work face and forming cavities in certain of the walls of the'passageway to increase the heat transfer area. 7

Other objects and advantages will be apparent from the following detailed description when considered in conjunction with the accompanying drawing, wherein Fig. 1 is a fragmentary sideelevational view of a welding machine illustrating the invention:

Fig. 2 is a fragmentary vertical sectional view of the upper'electrode shown in Fig. 1 and illustrating onespecie of the invention, and

Figs. 3 and 4 are similar vertical sectional views of welding electrodes illustrating other speciesof the invention.

Referring now to the drawing attention is first directed to Fig. 1, which illustrates a spot welding machine ll including a stationary elec-' trode supporting arm II and a movable head l2 supported by. an arm It for vertical movement,

' to move-an upper electrode ll relative to a lower electrode it. .These electrodes may be included in a welding circuit (not shown) and may be substantially identical in structure as for as the .55

inc. increased transfer areas invention is concerned, they being provided with passageways for cooling fluids circulating through fluid lines It and is for the electrode li'and fluid lines 20 and 2i for the electrode i5.

Considering now the specific structure of the electrode l5, attention is directed to its contour shown in Fig. 2, it having a work face 24 at its outer end, the opposite end being tapered, as at 25, to flt into a holder 28. The holder 26 is provided with a cap 21, having an inner passageway (not shown) which provides communication with the fluid line it and a central tube 28 and an outer passageway (not shown) which affords communication between the fluid line I! and a chamber 30 of the holder 26. The tube 28 is supported by the cap 21 or by any suitable means :(not shown) and extends downwardly within a passageway Si in the electrode I! to a point near the work face 2t.

The passageway ii is formed in the body of the electrode in any suitable manner, such as by drilling. If the passageway 3| were left with smooth walls, a heat transfer area of a given size would be provided. However, this areais greatly increased through the step of sandblasting or other suitable means, to roughen the surface of the passageway 3| as indicated at "and form depressions and'proiectipns therein. In this manner the surface area of the passageway is substantially double that of the former smooth walls, and as a result the heat transfer area is greatly increased in size. Therefore, the

terial and further tend to agitate it in its travel into and out of multitudinous cavities, to more effectively cool the electrode, particularly the portion adjacent the heat generating surfaces. In Fig. 3, electrode 4| is similar in structure to the electrode ll excepting the formation of the passageway ll. thereof. In this embodiment the passageway II is formed, for example, by drillbeing provided by adding a plurality of cavities 42 at the lower extremity of the passageway it and projecting downwardly toward work face 43. Thus when the. electrode ll is mounted in the holder II, the

'coolingmatenalmaybeforcedtluoughthetube it in the directions of the arrows to a point adjacent the lower extremity of the passageway H, the force of the material causing portions of ments returns from the passageway in the electrode, through the chamber 30 in the holder 28 to the .fluid line is. In this embodiment the wall 1 of the passageway 4! may be smooth, yet the surface areas adjacent the heat generating portion of the electrode have been multiplied, thus increasing the effectiveness of the cooling fluid to decrease the temperature of the electrode.

In Fig. 4, electrode 56 is identical in structuro to the electrodes l5 and t excepting the forming of the passageway which in this embodiment is provided with a plurality of grooves or, which may be termed cavities, to increase the surface area subjected to the cooling fluid and to not only retard the fluid but to give it a turbulent efiect in its travel to more efllciently cool the electrode, particularly work face 53 thereof. Instead of a plurality of circular grooves, one spiral groove may be employed, ifso desired. Thiselectrode may be mounted in the holder 26 and receive the cooling fluid from the tube 28 in the same manner described regarding the structures shown inFigs. 2 and 3.

As previouslystated, the efiectiveness of the radient is in proportion to the area exposed to the cooling fluid and, as illustrated in Figs. 2. 3 and 4, the areas exposed to the cooling fluid have been greatly increesed'so that the amount or.

understood that they, are but illustrative and that various modifications may be made therein without departing from the scope and spirit of this invention as defined by the appended claim.

What is claimed is: A welding electrode comprising a body having a work face, a circular peway for a coolin fluid formed therein. the walls of which provide 9. heat transfer area terminating short of the work face, and a pluralityoi equally spaced annular grooves formed in the outer wall of the I passageway to increase the heat transfer area and to disturb the travel of the cooling fluid through the passageway to eflect reduction of the temperature or the work face.

RAYMOND E. POWEIL. 

